An introduction to Slackware packages

Stuart Winter

Sunday 27th Februrary FOSDEM 2005

[email protected] www.slackware.com Introduction: Slackware

• First released in 1993

• Slackware aims to be the most “-like”

• Simplicity and stability are of paramount importance

• is the project leader & sole maintainer Presentation agenda

• Introduce the basic structure of a Slackware package

• Package management tools

• Package naming, version numbering, build numbers

• Package guidelines & policies

• Package Build scripts

• Checklist to help produce Slackware compliant packages Introduction: Slackware packages

Slackware Linux consists of a variety of software packages that make up the distribution.

Slackware 10.1:

- 552 main packages ( slackware/ )

- 128 extra packages ( extra/ ) Overview of a Slackware package

● gzipped archives (.tgz files) containing the directory structure and files

● Contains post install scripts

● Contains package description

● Typically monolithic (all-in-one) packages Package management tools Introducing the Slackware package management tools Command line tools

• installpkg: install packages

• removepkg: remove installed packages

• upgradepkg: upgrade installed packages with new .tgz packages

• explodepkg: extract .tgz packages into the current directory Introducing the Slackware package management tools Curses based tools Package anatomy Package anatomy

Package naming scheme

packagename-version-architecture-buildnumber.tgz

Package names are either the name of a single program or a collection/bundle of utilities.

autoconf-2.59-noarch-1.tgz: a single application

tcpip-0.17-i486-29.tgz: a bundle of utilities Package anatomy

Package version numbers

Single programs: version number is that of the released software. autoconf-2.59-noarch-1.tgz

'Bundle' packages: version number usually relates to the most major piece of software contained within the package. tcpip-0.17-i486-29.tgz Package anatomy

Package architectures

The current official values are: noarch - architecture independent files such as config files i386 - for the i386 or newer The normal value i486 - for the i486 or newer i586 - for the i586 or newer Re-packaged binaries s390 - packages for the IBM s/390 mainframe

Slack/390 Package anatomy

Build numbers

• Supplements the major version number

• Changed only when the package maintainer makes a change Package Version Architecture name number Example:

First build: foo-1.56-i486-1.tgz Build number Second build: foo-1.56-i486-2.tgz Package anatomy

Exploding a package drwxr-xr-x root/root 0 2005-01-26 03:23:42 ./ drwxr-xr-x root/root 0 2005-01-26 03:23:42 etc/ -r--r----- root/root 608 2005-01-26 03:23:41 etc/sudoers.new drwxr-xr-x root/root 0 2005-01-26 03:23:42 usr/ drwxr-xr-x root/bin 0 2005-01-26 03:23:42 usr/bin/ -rws--x--x root/bin 93056 2005-01-26 03:23:41 usr/bin/sudo drwxr-xr-x root/root 0 2005-01-26 03:23:42 usr/doc/ drwxr-xr-x root/root 0 2005-01-26 03:23:41 usr/man/ drwxr-xr-x root/root 0 2005-01-26 03:23:41 usr/man/man5/ -r--r--r-- root/root 18214 2005-01-26 03:23:41 usr/man/man5/sudoers.5.gz drwxr-xr-x root/bin 0 2005-01-26 03:23:41 usr/sbin/ -rwxr-xr-x root/bin 61352 2005-01-26 03:23:41 usr/sbin/visudo -rw-r--r-- root/root 561 2005-01-26 03:23:42 install/doinst.sh -rw-r--r-- root/root 869 2005-01-26 03:23:42 install/slack-desc Package anatomy

Exploding a package: package description

sudo: sudo (give limited root privileges to certain users) sudo: sudo: 'sudo' is a command that allows users to execute some sudo: commands as root. The /etc/sudoers file sudo: (edited with 'visudo') specifies which users have access sudo: to sudo and which commands they can run. 'sudo' sudo: logs all its activities to /var/log/ so the system sudo: administrator can keep an eye on things. sudo: sudo: sudo: Package anatomy

Exploding a package: post installation scripts

Two types of post installation script: install/doinst.sh: - non-interactive

/var/log/setup/setup.: - curses based interactive script

/var/log/setup/setup.onlyonce.: - run once only from the OS installer - last used in 1993/1994 era – now deprecated Package anatomy

Package policies & general guidelines

• Major binary directories are chown root:bin • gzipped info/man pages and Kernel modules • Hard links converted to soft links • Soft links converted to code within install/doinst.sh • Stripping of static archives, shared objects & binaries • Deletion of perllocal.pod files • HTML man pages removed from /usr/doc if there is /usr/man counterpart • /usr/{doc,info,man} – not FHS (Filesystem Hierarchy) compliant Package anatomy

Package dependencies

• Full installation of Slackware is the recommended option

• Official Slackware package tools do not handle dependencies

• Dependencies can be noted in the slack-desc or in config files

• a/aaa_elflibs package satisfies core dependencies

• 3rd party packages can help with dependency resolution but will remain unsupported. Packages may require additional metadata. Building packages Building packages

Build scripts: basic process prepare build location/directory

prepare packaging location extract source archives

configure source compile software

install components into the packaging location

apply the policies to the package contents

create a binary package (.tgz) Building packages

Introducing makepkg

• Produces .tgz packages from the contents of the $PWD

• Converts soft links to shell script code

• Checks for zero length files Convert soft links to script code Normal syntax:

# makepkg -l y -c n /tmp/foo-3.0-i486-1.tgz

Do not reset perms & ownerships Building packages

Two types of build script

SlackBuild 'Clean' package building scripts:

- Compiles software - Installs package contents into a special build location - Creates a binary .tgz package

.build 'Dirty' package building scripts

- Compiles software - Installs onto the root filesystem! Building packages

Build notes

• Packages are always built on 'disposable' development machines

• Slackware packages are always built as root

• All packages are built on a full installation of Slackware

Most build scripts are available in the source directories of each package. Building packages

SlackBuild scripts

• Reproducible package builds

• Simple '' shell scripts – no external calls to macros/functions

• Understandable at a glance and (usually) well commented

• Installs package into a pseudo root directory

• Sets Slackware packaging policy

The preferred method. Building packages

SlackBuild scripts: example Can override VERSION=2.4 at shell ARCH=${ARCH:=i486} BUILD=${BUILD:=1} setup build locations & extract source ./configure --prefix=/usr make make install DESTDIR=/tmp/package-foo Perms, ownerships install docs into package stripping, gzipping set Slackware packaging policies makepkg -l y -c n /tmp/foo-$VERSION-$ARCH-$BUILD.tgz To compile the software and build the package: Run from # ./foo.SlackBuild source dir Building packages

.build scripts

• Very basic shell scripts

• Do not set Slackware packaging policies

• Installs onto the root file system

• Does not produce packages!

• Used when the software's build system has no provision for installing into pseudo root location Replaced with • Gradually being phased out of Slackware SlackBuilds Building packages

.build scripts: example setup build location & extract source ./configure --prefix=/usr make make install install docs onto the filesystem

To compile the software and install onto the filesystem:

# ./foo.build Building packages

.build scripts: the process of package building Log files & dirs on filesystem Run .build script Differences = Log files & dirs on filesystem package contents diff both logs

Copy the differences to a pseudo root directory

Set Slackware policies within the pseudo root directory

Make a .tgz with makepkg Building packages

Creating packages from .build scripts: slacktrack

• Originally written to be ARMedslack's primary build tool • Slackware specific – only produces .tgz • Can apply all Slackware packaging policies • Can build replica packages from Slackware's .build scripts • Can be found in 'extra/slacktrack' in recent Slackware releases • Uses to track the installation Tracks filesystem • An alternate version is available: altertrack changes Building packages

Creating packages from .build scripts: slacktrack

Set Slackware policies

Example usage: Build script

# slacktrack -Qp foo-2.5-i486-1.tgz ./bar.build

Package name Building packages

Package building checklist Non FHS • Directory locations compliance

• install/slack-desc package description file 13 lines , 70 chars wide • install/doinst.sh post installation script Relative paths; • Binaries, shared & static libraries stripped ash compatible

• Permissions & ownerships / = chmod 755, root:bin bin dirs & files • Man pages: gzipped with no broken soft links

• Compare your package with the official .tgz (if applicable) Summary

• Simple 'bash' build scripts

• Two types of build script: SlackBuild and .build

• Build scripts available in source tree

• Read the 'OVERVIEW' file included with slacktrack to learn more www.slackware.com